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By F. Brost

In 1976, a decision was made to install a conveying system to transport ore 10.3 km (6.4 miles) from the new Eisenhower Partnership Mine to Twin Buttes. The system, supplied and installed by Cable Belt Limited, of England, represents a radical departure from conventional conveyor systems. The driving tension is applied through two endless wire ropes while the belt acts only as the carrying medium. Features of the system are a single 2240 kw (3000 hp) drive and a 60° angle bend. Construction was completed in two years. Full production was attained after several months' operation.

Jan 1, 1979

By L. L. Chasko, D. W. Alexander

Los investigadores del National Institute for Occupational Safety and Health’s Office of Mine Safety and Health Research han evaluado los efectos que la malla de control de suelos podría tener en la distribución de polvo flotante de roca y carbón en minas de carbón. El creciente uso de mallas para controlar el desconchado o caída de material del techo y las vigas introduce superficies elevadas adicionales para recolectar el polvo de roca o de carbón. Es posible que el potencial para la propagación de explosión del polvo se incremente si el polvo flotante de carbón no es convertido en inerte de manera adecuada. Adicionalmente, la malla podría interferir con la recolección de muestras representativas de polvo cuando se usa el método de recipiente y brocha desarrollado por la U.S. Bureau of Mines y usada por la Mine Safety and Health Administration para muestreo de banda. Este estudia hace una estimación del polvo de roca o carbón adicional que pudiera acumularse en la malla y desarrolla un método para recolectar muestras de polvo representativas atrapado en las mallas.

Jan 1, 2014

By S. S. Wang

Dialkyldithiophosphinates are a new class of flotation collectors for base metal sulfide ores. Structurally, they are quite different from the conventional collectors such as mercaptans, xanthates, thionocarbamates and dithiophosphates. Collectors Structures [Mercaptans R-SHS Xanthates R-OCS-M+ Thionocarbamates R-OCNH-R Dithiophosphates 2 R-CCNH-R' Dithiophosphinates (R) 2-PS-M+ ] In the above structural formula, R and R' stand for a hydrocarbon radical, and M+ is an alkali metal or ammonium cation.

Jan 1, 1982

By Fangyu Liu

In the grand tapestry of scientific inquiry, there are individuals whose contributions resonate far beyond the confines of laboratories and lecture halls. It is with profound admiration and respect that we present this special collection of Mining, Metallurgy & Exploration, dedicated to celebrating the remarkable career of Dr. Patrick Taylor. Dr. Taylor, recently retired from the Colorado School of Mines as the Emeritus Ansell Distinguished Professor of Chemical Engineering, possesses over 45 years of expertise in mineral processing and extractive metallurgy. His remarkable journey has seen him traversing the globe, from Canada to Egypt, contributing to pyrometallurgy, hydrometallurgy, and mineral processing. Dr. Taylor’s portfolio encompasses lab work, pilot-plant projects, research, and process development across various metals, with an impressive array of authored papers, presentations, and nine patents to his name. A soughtafter consultant for over 20 companies and an esteemed expert witness, Dr. Taylor also led the Kroll Institute for Extractive Metallurgy at Colorado School of Mines. Under his guidance, more than 100 graduate students and post-docs have undertaken transformative research, while Dr. Taylor’s 45-year tenure as a university lecturer and the creation of 10 industryfocused short courses underscore his dedication to knowledge dissemination. His contributions extend to crafting professional engineering exam questions for a quarter-century and active participation in esteemed organizations like SME, TMS, ASM, and MMSA.

Sep 16, 2023

By R. L. Morse

The thermodynamic program is similar to previous mine ventilation programs but has been expanded to consider the compressibility of air. The thermodynamic program does consider: 1) air density variations, 2) humidity changes, 3) intake, exhaust, and underground fans, 4) heat transfer between rock and air, 5) refrigeration of heating plants, both surface and underground, and 6) heat generated by equipment, both diesel and electric. 110st of the compressibility factors are handled in the branch calculations. The field survey necessary to supply-data for this program is quite similar to the basic base and leap-frog pair of stations method used with most incompressible mine ventilation programs. The thermodynamic program is a complete package of ventilation network analysis which can provide mine management with good operational control and planning of mine ventilation systems.

Jan 1, 1977

By M. Sadegh Safarzadeh, Erich U. Petersen, Jan D. Miller

"An acid bake-leach process has been identified and applied to an enargite concentrate containing ~67% enargite, ~27% pyrite (FeS2), ~3% chalcopyrite (CuFeS2), ~6% sphalerite (ZnS) and <1% galena (PbS). Sulfuric acid baking of this concentrate resulted in the transformation of the concentrate to S8, As2O3, HFe(SO4)2•4H2O, PbSO4 and Cu0.47Fe0.53SO4•H2O, all of which (except elemental sulfur and PbSO4) dissolved during the water leaching step. More than 87% Cu and 64% As were leached when the concentrate was baked at 200°C over 7 hours with a sulfuric acid-toconcentrate weight ratio of 1.6. Less than 1% As was lost to the gas phase. Upon water leaching, copper and arsenic were released to the solution at a concentration ratio of about 3:1. While enargite is very reactive during the sulfuric acid baking reaction, other minerals present in the concentrate such as pyrite, galena and sphalerite may compete to consume sulfuric acid and be converted into their corresponding sulfates at different concentrations. The purpose of this paper is to present our examination of the effects of sulfuric acid dosage on the extractions of Cu, Fe, and As from an enargite concentrate. In this regard, the concentrate, baked concentrate, and the leach residues are characterized and a conceptual process flowsheet is described for the acid bake-leach process for the treatment of enargite concentrates.IntroductionThe occurrence of enargite (Cu3AsS4) in copper ores and concentrates and the associated high arsenic values in such resources have resulted in a considerable decrease in the demand for such concentrates because they cannot be economically processed using conventional technologies such as smelting and atmospheric leaching (Mihajlovic et al., 2011). The exploitation of such problematic deposits through competitive treatment strategies will be required in the near future in order to satisfy increasing pressure from the copper market. It is expected that the average arsenic grade of copper concentrates will increase from 0.17% in 2008 to 0.22% by 2020 (Mayhew et al., 2011).The acid bake-leach process was identified and selected for further investigation at the University of Utah as a possible process alternative for the treatment of enargite concentrates. In this case, adequate amounts of concentrated sulfuric acid are mixed with the concentrate and heated to the temperature range 150-300°C. Subsequently, the baked material is leached with water/weak acid and the acid bake-leach process has some advantages over conventional sulfuric acid leaching (Prater et al., 1970). During water leaching, metal sulfates are released in solution, after which they can be extracted through well-known hydrometallurgical techniques. While the majority of the work has been done on oxide minerals, there is a limited record of sulfuric acid baking of sulfides."

Jan 1, 2015

The mining industry, like most other industries, has had a difficult couple of years. What are your thoughts on the industry?s direction in the next few years? I am bullish on our industry. There is no question in my mind that the quality of life we enjoy today is largely a result of our past successes in the minerals and mining sector. I am equally certain that the sustainability of that quality of life and the aspirations of the rest of the world to attain that same level of lifestyle will depend hugely on our future successes and will be the driver for our industry to continue to excel and prosper. Surely, there are going to be challenges along the way. These challenges are not only from the public, regulators and various governing bodies, but also from our industry?s own self regulating efforts. However, we have demonstrated throughout the past several decades that we have the capability to meet these challenges head on and come out ahead.

Jan 3, 2010

By Sunfangze Liu, Xumeng Chen, Yongjun Peng

Efficient separation of naturally hydrophobic gangue, such as talc and carbonaceous materials, from sulphide minerals in flotation is becoming a significant challenge in many processing plants due to the need to process lower grade and more complex ores. Considering the hydrophobic nature of these gangue minerals, prefloating them at the beginning of the flotation circuit in the absence of collectors and rejecting the concentrate is a common practice to remove these gangue minerals. However, sulphide minerals, such as chalcopyrite, can become naturally floatable due to surface oxidation and therefore may float together with naturally hydrophobic gangue. In this study, a new approach was developed to maximize the prefloat of hydrophobic gangue while minimizing the loss of sulphide minerals. The new approach introduced a prefloat cleaner stage where sulphide minerals recovered to the prefloat concentrate was depressed and separated from other hydrophobic gangue minerals at a low pulp potential with the prefloat cleaner tailing fed back to the main sulphide flotation circuit. Flotation tests were conducted using chalcopyrite and organic carbon. The results show that the proposed approach can significantly reduce the loss of valuable minerals in the prefloat flotation without affecting the reject of naturally hydrophobic gangue. Applying pulp potential control at the prefloat cleaner flotation stage also reduces the consumption of reducing agents while minimizing the effect of reducing agents on downstream rougher flotation.

Nov 23, 2020

By S. Philipp

This paper describes several variants of placement and design, from a technical and economic point of view, of shafts, ore bunkers and drifts near shafts of a Russian potash mine. Advantages and disadvantages of the position of different workings are shown as well as an analysis of stratigraphic and geological layers and their use for excavating pit bottoms, haulage drifts and bunker installations. The potash mine consists of two hoisting shafts and one service shaft. The hoisting capacity of one of these skip shafts is planned to be approx. 7 Million tons of crude potash salt per year. Both shafts together will have a hoisting volume of about 14 Million tons. When the mine will increase their highest level of production, it will be one of the biggest potash mines in the world. The skips, the hoist drives and the bunker near the shaft will belong to the largest ones worldwide, too. This paper specifies the features of such a double skip shaft pit in detail and demonstrates problems, which depend on the fact that the pit bottom is in a depth of nearly 1200 m.

Feb 23, 2014

By H. Russell, N. DePriest, J. D. Quaranta

Valley-fill structures built of blasted rock overburden from Appalachian mountaintop surface mines pose many reclamation challenges. The steep mountainous terrain, short valley lengths, and straight stream channel profiles create significant challenges to implementing fluvial geomorphic landform design in terms of both form and function, and from a safety and constructability perspective. The fluvial geomorphic landform design approach balances erosive and resistive forces by considering long-term climatic conditions, soil types, slope profiles and vegetation types. Commercial geomorphic landform design software tools do not specifically analyze the stability and factor of safety for the computer-designed landform slopes. This research investigated slope stability parameters and factors of safety between a traditional valley-fill design with a geomorphic landform alternative. Slope stability assessments were performed on two profile geometries. Finite-element modeling of a permitted valley-fill and a geomorphic design alternative indicated that slope angle and internal angles of friction associated with the gradation of the overburden greatly affected the designed factor of safety for both designs. The geomorphic designed slopes yielded the highest factors of safety out of 14 models analyzed with all cases having factors of safety over 2.0. The high factors of safety are attributed to shallow slopes and beneficial surface and internal drainage.

Jan 1, 2014

By Euclid P. Worden

In 1977, an article in World Mining (1) reported a total of 2726 rotary blast hole drills in service. This figure included only those machines produced by three of the manufacturers building drills of this type. The total, therefore, is much higher: Rotary drilling in the mining industry is big business to the manufacturers and suppliers involved, and a significant cost item, to mine operators. The time has come to take a hard look at rotary drilling technology with an eye to re¬ducing costs by increasing drilling efficiency. The efficiency of any rotary drilling operation is measured in terms of the rate of penetration achieved by the bit. In blast hole drilling, five factors affect the rate of penetration. They are: 1. Bit selection 2. Weight on the bit 3. Rotary speed 4. Hole cleaning 5. Formation properties Of these factors, all but one may be control¬led by the operator. Looking at any one in detail may reveal possible improvements in the system. Cleaning the hole is a good place to start. In order for a bit to perform at its maximum capability, each tooth or insert should strike fresh, clean rock as it falls into its drilling position. If the tooth or insert lands on previously drilled cuttings, a major portion of the energy delivered to the bit is absorbed in re drilling this broken material. A major portion of the interest, therefore, should be directed to the proper cleaning of the bottom of the hole.

Jan 1, 1979

By Donald Towse

Geothermal heat might become an important fuel for several reasons: (1) To substitute for other scarce and critical fuels. (2) Because it may be less costly to the user than alternate fuels. (3) Because its production may be more profitable than production of other fuels. (4) Or for a number of other more or less non-economic reasons such as convenience or because of less environmental impact. In competition with conventional and other non-conventional fuels, geothermal heat must score well on one or more of those points. This study first considers projections of energy needs in several United States economic sectors and the technical possibility of geothermal heat substituting for other fuels in those sectors. Then, reported and projected costs of energy from geothermal heat are compared with costs of other fuels to show the relative costs of fuels in several economic sectors. Relative costs are reported from a sample of real and hypothetical geothermal projects. The actual cost of energy will vary with each application and the particular circumstances of each geographic location.

Jan 1, 1975

By R. DasGupta

The dissolution behavior of gold in ammoniacal solutions at 75°C has been investigated. The variables investigated include concentration of lixiviants, pH of the solution and various oxidants. The anodic dissolution of gold was studied in the absence of oxidants using the potentiodynamic polarization technique. The cathodic reaction of oxidants was studied on a platinum electrode. Tafel polarization tests were also performed to determine the dissolution rate. The overall dissolution of gold in ammoniacal solutions was examined using a mixed potential theory. A comparative study on the role of cupric am mine, oxygen, hydrogen peroxide, sodium hypochlorite as oxidants for the dissolution of gold in ammoniacal solutions has been carried out.

Jan 1, 1996

By Zsolt Csillag, Dragorad Ivankovic, Miomir Ceh, Anna Csordás-Tóth

Results of the common research work of ALUTERV-FKI and RI in field of ore dressing are presented here. Although monohydrate types of bauxites consist of finely dispersed minerals, however, in some cases certain contaminants (carbonates mainly), can be reduced by physical methods before Bayer process. Electronmicroscopy combined with computerized data processing is proven to determine the possibility of beneficiation and to control the different stages of ore dressing. Test results gained by Hungarian and Yougoslavian bauxite samples, contaminated by calcite, dolomite, siderite and pyrite, are discussed. Basic operations were: grinding (mostly dry) and classification, magnetic separation (mostly wet) and selective agglomeration. Only simple processes, having high efficiency and mostly dry ore dressing technique may meet the requirement of economical criteria. 1. [CONDITIONS OF ADAPTING THE BAUXITE DRESSING METHOD] Bauxite is a relatively cheap raw material, occurring in great bulks. Bauxite deposits may often lay far from the traditional ore processing plants, and in such cases the ore reaches the plants after long transportation. Some of these plants must face the difficulty that the resources of high quality ore are exhausted, they fall short of supply and, consequently, they must decide on whether to utilize the existing resources of poorer

Jan 1, 1984

By Frederico J. Price

This paper describes the production of a specific iron oxide pellet that has given very good and consistent results as feedstock for HYL-Process Direct Reduction Plants. The sponge iron originated from these pellets has been used for the economic making of almost 15 million tons of low carbon steel via electric arc furnace meltshops. An overview of mining, benefication, pelletizing direct reduction and steelmaking for this case is given with emphasis on the characteristics of the self-fluxing oxide pellets. HYL Operator and management training is described.

Jan 1, 1979

By Nikhil Dhawan, Shrey Agrawal, Ashwini Kumar

The current study investigates sericite clay as an alternative source of potash and alumina. The alumina and potash content in the sericite is approximately 35 and 10%, respectively, compared with 50–55% in bauxite ore. Muscovite and illite phases are stable, and direct leaching is found to be ineffective. Here, planetary ball milling was performed, which provided dissociation of stable phases to relatively reactive phases. The milling led to a five-fold increase in the surface area, resulting in enhanced leaching kinetics even at low acid concentration. The statistical design obtained optimal conditions of 8 h of milling followed by leaching in 1.73 M HCl at 75 °C, yielding 82% alumina extraction in precipitate with 85% purity in γ-alumina form and 63% potassium dissolution in sylvinite phase. The yield of the precipitate was ~65–68%, and the acid leach residue contained primarily silica.

By I. J. Dowdeswell

Perspective Man is a model maker. Throughout recorded history man has-used models both to provide insights into the workings of the processes which surround him and as a step towards the eventual control of those processes. These models have covered the field from extremely large systems (solar and celestial. models) to infinitesimally small systems (sub-atomic .and atomic models). Models have been developed for social systems, ecological systems, biological systems and economic systems: all fields of human endeavour contain the fruits of this restless model-making. The Role of Models Since the evidence of mans&apos; industry in formulating models is so abundant, it is worthwhile stating some of the reasons. Based on the simple definition that "a model is a convenient and useful representation of some facet of the &apos;real&apos; world", then a model provides a means for: 1. Understanding the thing being studied. 2. Communicating that understanding to others. 3. Manipulating the thing being modelled. The common denominator implicit in these reasons is that- improved control is the. objective off all modelling or simulation work. Improved control shows itself either directly by the development of devices which perform the control functions or indirectly by improvement in the decision making process itself. For example, in a process plant, a suitable model of part of the process could lead either to the use of automatic control devices such as set-point controllers or to the implementation of instructions (pre-defined decisions) which permit the operator to better control the process. Typical process control systems use both of these since fully automatic control is restricted to processes where the required information can be effectively measured.

Jan 1, 1972

By D. P. Bryan

An aggregate resource study was done for southern Washoe County, Nevada, which contains the Reno-Sparks metropolitan area and a population of about 300,000. The study included an inventory of existing operations, projection of future demand, identification of potential aggregate resources based on geology, and determination of economic potential of these resources. Economic potential was determined by the integration of GIS layers that included aggregate potential, distance from market, distance from major and minor transportation arteries, and elevation. The investigation resulted in a determination that resources of high quality aggregate sufficient for future consumption are present in southern Washoe county; the limiting factor for future utilization is accessibility.

Jan 1, 1996

By B. R. Benner

Progressive improvements in crusher design, screening efficiency, and operating experience along with the downsizing of many taconite operations has resulted in the abilitv of some crushing plants to produce a substantially finer product. This finer product opens the possibility of replacing the rods in the rod mill with balls as is the current practice at Sydvaranger, Norway. If this replacement could be accomplished substantial savings associated with metal wear and the elimination of rod charging may be realized. The purpose of this study was to compare the performance of a mill charged with rods with the performance of the same mill charged with balls at the pilot scale. The first objective was to establish whether we could achieve the same throughput rate at the same mesh-of-grind in a mill in which the rod media has been replaced by balls. The second point was to determine whether the ball media would create a significant tramp oversize problem.

Jan 1, 1990

By Jurij Karlovšek, Marko Žibert, Scott Keniston

"SUMMARY The importance of information management was recognised in surface construction industry decades ago, and has increasingly being recognised through formal process and laws. Around the world, these laws and codes of practice are currently being drafted and enacted, to reflect the development of software tools and corresponding increasing adoption by industry. This paper deals with specifics of implementing information modelling in tunnelling business utilising BIM (Building Information Modelling) technology developed for buildings as well as similar technology developed for mining industry. Although BIM is recognized initially as a 3D digital representation of physical and functional characteristics of a facility, the real benefits come when complex capability through construction sequencing and even detailed programming (4D) and cost capabilities (5D) are included. INFORMATION MODELLING The Architecture, Engineering and Construction (AEC) industry requires the production of design and construction information, which involves the input from several teams. The tasks allocated to each team need to be carried out in a particular order and coordinated in order to benefit all those involved and the project itself; this is known as “collaborative working”. To ensure the quality, and guarantee that information can be used without change or interpretation, working processes and standards needs to be agreed upon or else it will hinder collaboration and have a negative impact on project delivery. Case studies show that the additional capital delivery costs due to uncoordinated, inaccurate and ambiguous information amounts to 20-25%. The solution to overcome these problems and improve collaborative working in a project is the adoption of BIM. It is a modern approach to the design, documentation, delivery, and life cycle management through the use of project information databases coupled with object-based parametric modelling. BIM requires traditional practices shifting from simple drafting to using 3D native models for building design environment. Additionally, it requires that models are equipped with information that has been traditionally decoupled in a text or other kinds of documents. The goal is not in creating a 3D graphic representation of design intent; rather, it is a comprehensive information management tool based on the simulation of design and construction build around a central repository."

Jan 1, 2016